Mark Hendrick, the Labour MP for Preston who chairs the all-party China group, was out of Britain on visits for more than four months in total since 2010. He took seven foreign trips costing £43,211, including a month-long stay in Beijing where he learnt Mandarin. Andrew Rosindell, the Conservative MP for Romford, went on £25,000 worth of trips to the Cayman Islands, the Turks and Caicos Islands, Switzerland, Taiwan and Uzbekistan, among other countries.

The findings, published by The Independent, also showed that:

Š One in five Conservative back-bench MPs have visited Israel and Palestine since 2010. Most of these trips were funded by pro-Israeli lobbying organisations. Some 79 MPs have gone to the region on visits costing their hosts more than £130,000.

- Twelve MPs went on a four-day trip to Riyadh, costing their Saudi Arabian hosts £36,000.

- MPs accepted trips to Azerbaijan, costing a total of £41,000.

- There were 36 MPs’ visits to China and Hong Kong, 23 trips to India and 34 trips to the US since the general election.

- Six MPs have been on trips to Australia, five to Brazil and three to the Cayman Islands.

- Only one MP accepted a trip to Afghanistan during the period concerned and only two visited Belgium.

The MPs insisted that they always tried to take the trips when Parliament was not sitting, and defended the visits as an important means of fact-finding and strengthening UK relationships abroad.

But Sir Alistair Graham, the former chairman of the committee on standards in public life, said: “My worry is when you have MPs taking large numbers of trips they give the impression that they are taking every freebie that is around. And that, I fear, would have to come at the expense of their constituents.”

A spokesman for David Miliband said a number of his trips were during weekends or during recess so he only missed 13 days from Parliament.

Mr Hendrick stressed that his visits were all made for political and economic reasons and were carried out during parliamentary recesses.

Mr Rosindell said all his overseas visits were linked to his parliamentary duties.